Earlier today, we discovered an overdue maintenance check required to be performed on the standby hydraulic system, which serves as a back-up to the primary hydraulic systems.

Southwest inadvertently omitted the lowest of three intervals for the maintenance check, it was a conservative interval that was established within Southwest’s FAA-approved maintenance program. As a result of this discovery, 128 -700 aircraft were identified as having overflown the required check.

The grounding did not last long, however. After cancelling just under 100 flights late Tuesday the company announced early Wednesday morning that it has reached an agreement with the FAA which will allow the planes to keep flying over the next five days while the inspections are completed. Some flights may be affected during the inspection window but all indications are that Southwest plans to run as close to a normal schedule as possible. Bot operating redeye flights should help the company in terms of minimal cancellations and getting the aircraft through the inspection process inside of the five-day window allotted.

This is not the first time Southwest has missed inspections, though it has been a while since the last significant dust up over similar issues In 2008 the company flew 44 planes on approximately 60,000 flights on planes out of the inspection window. At that time things got ugly both commercially and politically for the carrier. Further maintenance missteps earned the company millions of dollars in fines as recently as 2014. This time around, at least so far, it is just a PR issue, though the possibility of fines or other sanctions remains.